1. Field of Invention
This invention concerns the oxidative water, process, and equipment suitable for cleaning, sterilization, and wound healing.
2. Related Art Statement
The anode water produced by electrolyzing saline solution is reported to be useful for cleaning, disinfections (sterilization), and wound healing.
The anode water with the oxidation and reduction potential, hereinafter abbreviated to ORP, higher than 1100 mV is reported to kill microorganism effectively and attracts the attention in the fields of disinfections (sterilization).
In general, an electrolysis device containing a two-compartment cell composed of an anode and a cathode compartment as shown in FIGS. 15 and 16 is used to produce the anode water suitable for disinfections or sterilization. In the FIG. 15, the number 51 indicates an anode compartment; the number 52 indicates a cathode compartment. The separate membrane 53 of cation exchange membrane separates the anode compartment from the cathode compartment. The number 54 and 55 indicate each an anode electrode and a cathode electrode. Saline water is fed to inlet 51a and 51b of the cell. The anode water is supplied from the outlet 51b in the anode compartment. The cathode water is supplied from the outlet 52b in the cathode compartment after electrolysis.
The reactions in the anode compartment 51 are as follows:2Cl−−2e−→Cl2  (1)2H2O−4e−→O2+4H+  (2)Cl2+H2O→HClO+HCl  (3)
The reaction in the cathode compartment 52 is as follows:2H2O+2e−→H2+2OH−  (4)
As clear FIG. 16, chloride ions move from the cathode compartment to the anode compartment and then anode water exhibits acidic pH. Cathode water always exhibits alkaline pH because sodium ions move to a cathode compartment from an anode compartment.
Anode water produced by electrolyzing saline water is used to kill microorganisms. The killing power of the anode water is enhanced as the ORP increases. In order to increase ORP, the electrolysis current should be increased.
Then, as the electrolysis current increases, the transfer rates of sodium from an anode compartment to a cathode compartment and chloride ions from a cathode compartment to an anode compartment are increased. The concentration of chloride ions in the anode compartment increases and so the pH of the anode water becomes strongly acidic.
The strong acidity causes sever corrosion on the surface of some metal and is considered to be demerit. For example, ferrous metal severely corrode under acidic pH less than around 3. In order to prevent metallic corrosion, the pH of anode water is desired to be neutral such as around 7.
In addition, the anode water with neutral pH almost same as the pH of blood or fluid of body is suitable to treat patients after surgery by medical doctors or nurseries. However, when two-compartment cells are used, the pH of anode water with ORP higher than 1100 mV is lower than 3 and so strongly acidic. Anode water produced by two-compartment cells is very acidic and corrosive.
The three-compartment cell composed of an anode compartment, a cathode compartment, and a middle compartment between an anode compartment and a cathode compartment was invented to overcome the demerit of two-compartment cell. FIGS. 1,2, and 3 show schematically the new device containing the three-compartment cell. FIG. 1 shows schematically the important components of the device. FIG. 2 shows the top-view of electrode. FIG. 3 shows schematically whole device.
In the figures, the number 1, 2, and 3 show each the anode compartment, the cathode compartment, and the middle compartment. The anode compartment 1 is separated from the middle compartment 3 by the separate membrane 4. And the cathode compartment 2 is separated from the middle compartment 3 by another membrane 5. The number 5 and 6 indicate each the anode electrode with many holes and the porous cathode electrode with many holes as shown in FIG. 2. These electrodes 5 and 6 are closely attached to the membranes 4 and 6. In addition the anode electrode 5 is located in the anode compartment 1 and the cathode electrode 6 is located in the cathode compartment 2. Glass beads or ion exchange resins are packed in the middle compartment 3. When the electrolyte solution containing halogen ions such as chloride ions is supplied to the middle compartment 3 the resistivity of cell is lowered and so glass beads can be used in place of ion exchange resins.
The number 1a and 1b show each the inlet and outlet of the anode compartment 1. The number 2a and 2b shows each the inlet and outlet of the cathode compartment 2. The number 3a and 3b show each the inlet and outlet of the middle compartment. The number 8 indicates the pipe connecting to the inlet 1a and inlet 2a is used to feed the cell with water. The number 9 indicates the pipe connected to the inlet 3a and 3b for circulating the electrolyte solution in the tank 10 through the middle compartment 3, such as saline, by using the circulation pump 11. The anode water produced is stored in the storage tank 12 that is connected to the outlet 12 of the anode compartment 1 through the pipe 13.
Electrolyte solutions such as saline are not fed directly to the anode compartment 1 or the cathode compartment 2. Although the concentration of salts in anode water is considered to be low, compared with two-compartment cell.
The anode water inevitably exhibits still acidic pH because some quantity of chloride ions is transferred from the middle compartment 3 to the anode compartment 1.